Removal of Emerging Contaminants from the River Mantaro: Implications for Safety

The study investigates the enhanced properties of Chak'o nano-clay following amine functionalization and polymeric coating, which were employed for the selective removal of pharmaceuticals, pesticides, and heavy metals from the Mantaro River water in Peru. Adsorption experiments were conducted under varying conditions, including dosages ranging from 0.5 to 2.0 g/L and contact times between 1 and 6 hours. The results demonstrated that the modified Chak'o nano-clay achieved a diclofenac removal efficiency of 92.4%, an atrazine removal efficiency of 93.0%, and a lead removal efficiency of 99.5% under optimal operational conditions. The maximum adsorption capacities of the surface-modified chak'o nano-clay were found to be 45.6 mg/g for diclofenac, 48.3 mg/g for atrazine, 120.7 mg/g for lead, and 104.3 mg/g for cadmium. Kinetic analysis indicated that the adsorption data adhered to a pseudo-second-order model, while the Langmuir isotherm provided the best fit, suggesting that the adsorption occurred on a monolayer of active sites. The reusability of chak'o nano-clay was notably high, retaining more than 85% of its adsorption capacity after five complete adsorption-desorption cycles. Post-treatment water quality met food processing standards, with reductions in turbidity, mineral content, and microbial pathogens. These findings highlight that surface-modified Chak'o nano-clay represents a promising, sustainable water purification technology capable of removing multiple contaminants, thereby ensuring the safety and quality of water used in food processing in regions impacted by water pollution.